Hello to all (especially to 727 folks)!

[3-Holer]

Hello,

With 2008 around the corner, I figured it was time to join the forums for the new year.

A quick introduction:

My project is not quite a sim but, rather, a historical and technically accurate restoration of a 727-100 cockpit (sort of). I have a real -100 main instrument panel (MIP), overhead (100% filled with correct modules), throttle quadrant, and control columns plus yokes at present. The MIP is now 100% filled with correct analog instruments and warning lights. This will be a working restoration which means I intend to have all instruments/lights fully functional. However, in order to preserve the historical restoration, I am working to one simple rule, which is: "no instrument or component is to be modified in any way". This means I have to design interfaces to all instruments using their native (original) signal format. Being an Airframe and Powerplant technician, and an Aerospace electrical engineer, this is not particulary a major problem but it will require a lot of work (currently in progress).

My original intent was to have a working static display but the more I think about it, the idea of connecting the above to operate as a functional simulator makes sense. Once I have all the interfaces done, the next logical step would be to have Flight Simulator be the source to drive eveything in response to control inputs (i.e., flying). But, that part of the project is way off at the present time.

I also have all modules for the Flight Engineer station and will eventually get that going as well.

I also have quite a bit of 727 technical data to include flight manuals, aircraft maintenance manuals, aircraft wiring diagrams, and some instrument overhaul manuals in case anyone is looking for some technical information that is not otherwise readily available.

At the moment, I do not have any digital photos of the project but when I get some, I will post them.

If anyone has any questions, please let me know. I always like to share with others, especailly those who also like the 'ole 3-holer.

Happy holidays to all!!

Rick

[Westozy]

Welcome to MyCockpit Rick,

We have a few 727 sim builders here, it will be great to have your tech know how available for our members. Looking forward to seeing your pics.

Regards, Gwyn

[Michael Carter]

A big 'Welcome' from me. Glad to have you aboard.

I have some pin-out questions for some Gables equipment I'll bother you with after the holiday.

[Matt Olieman]

Oops!!! another 727 builder.... :) What's an airbus person, like myself, to do with all these 727 builders :) :)

Glad to have you aboard Rick, you're in good company :)

[Michael Carter]

It's nice to know there are more 727 builders that aren't afraid of a challenge. :lol:

I'd be willing to bet that if software and hardware development companies would support this aircraft, more people would build it. A smaller percentage for sure and prices would reflect that, but at least parts and pieces and software would be available.

I really shouldn't be complaining though. Surplus Boeing equipment is much cheaper than any aftermarket 737, 57, 67, 47 equipment. And it's the real part. Not something close, not 80% scale, no guesswork involved. If it has a Boeing or other mfg part number, you have the real deal.

The reverse engineering can sometimes be a PITA, and it helps to have a background in electronics, but it's by no means rocket science to hook up switches and get indicators working.

It's rather scary jumping in to uncharted waters with few, if any, that have gone before you.

If it hadn't been for Joe's incredible 727, I might not even have a simulator, because it was a 727 or nothing.

[3-Holer]

All,

Thanks for the comments! I'm glad to be here.

For Boeing Skunk Works -

Regarding Gables pin-outs; this is one manufacturer that I have no data for. Not sure why but their data is not readily available as is Collins. I've had to ring-out the pins on my Gable control heads instead of looking them up as I have for other components. For Nav/Com heads, it would be helpful to know the 2-out-of-5 standard that was used to define the frequencies on older aircraft before digital data buses. Basically, each digit of the frequency is defined by five discretes (five wires) where any two of them are grounded (logic 0) while the other three are held logic high. By varying the pattern of the two discretes that are grounded, the numbers 0-9 are defined for that digit. For the higher weight digits, like the 10 megahertz digit, several of the inputs are typically hard wired inside the control head since there will only be a few combinations used (e.g., 100 mhz (0), 120 mhz (2), 130 mhz (3)); no need to carry wires for discretes that never change.

Let me know what Gables questions you have and maybe I have something here that will help. One avenue I have used before is to use my aircraft wiring diagrams to help figure out pinouts of control heads and other things. Sometimes this works and sometimes not; the biggest problem is that the diagram does not identify the model of the control head, so sometimes is takes some deduction work to figure it out. I recently used this method to figure out the pinouts for my radio altimeter instrument (vertical tape type)that would have been a nightmare to figure out by reverse engineering.

Rick

[Michael Carter]

Hi!

Just one piece for now that I haven't had on the bench yet: Gables G-3859, 32 pin jack for the advanced WX radar controller.

I only need the pins for the lightplate and push-buttons. Would the indicator lamps in the PB's be 28vdc? Unlike Collins equipment, I've found that Gables uses both voltages for a lot of the indicators for their control heads.

If you don't have this info, no sweat. I'm used to probing with a meter.

The most difficult peice I had to figure out was the flight director control. I called a shop in Memphis and the guy was very helpful. It was only a 26 or 28 pin jack, but no matter what I probed, I couldn't find those two pins.

Thanks! :D

[Geremy Britton]

i would like to know how to backlight my panel. i bought an odd on from ebay becuase it was going realy cheap. it's a transponder i think from a 727 or similar.. it has 2 metal leg pins on the back that stick out about an inch. are these the backlight connectors and if so what voltage is the most likly they will take?

(sorry if i seem to be hijacking, but just a quick question i can slot in here whilst on topic;).)

geremy

[Michael Carter]

Can you post a photo? I'm not getting a mental picture of what you're talking about.

Most lightplates are five volts, but I have a couple of Gables radio source selectors that use the 28VDC. It's the only two I have that use that voltage, but you never know what's out there.

Try with 5VDC first, if it doesn't light, move up to 12. If it's dim, it's 28VDC.

[3-Holer]

BSW - I don't have any data for the G-3859 Radar head but I looked at one of your pictures to see which one you have; turns out that I have one very, very close to that model (G-2722). The light plate lamps are 5 VDC; I just verified the voltage before writing this but mine has two external connectors, so the pin outs are probably not the same as yours.

Regarding the six push buttons; my push buttons, which are labeled the same as yours, do not have lights in them. It sort of looks like there is a bulb in there but, in reality, it is just the drilled plastic that looks like a bulb. With the light plate bulbs on (night operation), any button that is pushed in lights up because it gets light from the side of the panel when it is pushed in.

737 GEZ - I take the same approach with bulbs as BSW suggested; try 5 VDC first and if very dim or not on at all, try 12 or 28 VDC. Most commercial airline equipment does not use 12 VDC as General Aviation does, so it is typically 5 or 28 VDC.

I suspect the two "pins" you are referring to are the connector alignment pins. Is the connector round or rectangular, like a PC 25-pin printer connector? The older heads and on some aircraft (e.g., DC-8) used these types of connectors and not the more traditional rounds ones we typically see. As BSW suggested, a picture would be very helpful. If the "pins" are, in fact, for alignment, they have no electrical function. There would be two pins on the connector itself that carry the voltage to the bulbs.

There are typically two different types of backlighting used on these heads, (1) bulbs mounted to the back-side of the plastic light plate and (2) bulbs mounted in sockets on the metal plate that the plastic lightplate mounts to. If #1, there will be a special connector on the metal plate with two wires on it located right beneath the little "+" that should be seen on the plastic lightplate front. If #2, you will see wires soldered to the several light sockets (which are wired in parallel) that are mounted to the metal plate (look on the backside). In either case, with the unit opened up, find the two wires that leave the bulb sockets (or special connector) that go to the external connector. You can do a continuity (resistance) check with an Volt-Ohm meter to identify the light pins. Put one lead on one of the bulb wires and the other probe on each of pins (one at a time) on the unit's external connector. When you get near zero ohms on one pin, you found the pin associated with that light wire. Change the meter lead to the other bulb wire and repeat the process, trying each pin again (except the one you already found); when another pin shows near zero ohms, you found the second light pin. If you hit the first light pin, the resistance will be higher then 0 but not as high as infinity because you are now measuring through the bulbs. This will also happen if you get to the "second" pin first before getting to the pin connected to the first wire you are measuring. Again, the higher resistance would be due to measuring through the bulbs. Of course, this presumes the light bulbs and/or light plate are installed at the time.

You would apply the 5 VDC (+) on one pin and (-) side on the other pin; the lights should illuminate. Polarity does not matter.

If you have any questions, please let me know; it sure takes a lot of words to explain a simple process. See if you can post a picture as well.

For all - I took some pictures of my 727 panels and will post them in a few days. I still use film, so you know the waiting process....

Rick

[Michael Carter]

Thanks for the info. That's pretty neat the way Gables designed the buttons on that head. It does look like there's bulbs in there.

The reason I go from 5VDC to 12VDC if I can't get any light out of the plate is that I'm scared I may have missed something during the probe and don't want to hit it with 28(24)VDC if in fact they really are 5VDC.

Although 12VDC might burn them up too, it may give me a half second longer to remove the probes.

You were explaining the bulb arrangement the different manufacturers use to light the plates; the radar display I just received is as you described with the bulbs actually being mounted in the equipment. The Collins 614's are the same way. Or was it the HF radio? Now I can't remember.:roll:

[3-Holer]

All,

Here are the pictures I promised; my restoration of a 727-100 instrument panel along with Overhead Panel and Throttle quad.

Rick

[Matt Olieman]

Fantastic Rick, what a wonderful project, excellent looking equipment, congratulations :)

[Michael Carter]

All,

Here are the pictures I promised; my restoration of a 727-100 instrument panel along with Overhead Panel and Throttle quad.

Rick

Very nice. Good to see another 727 instrument panel on this forum. Looks like home to me!

What is the module between the anti-skid and Flight Control Warning Test module in the left bay of the overhead?

If you need a -100 landing gear panel (less acuator) let me know. I might have a contact with one that is particular to the -100 series. I know the light arrangement is different for that varient.

[3-Holer]

The module above the Anti-Skid panel is "GPWS--OFF, NORM". [GPWS=Ground Proximity Warning System]. The switch cover is typically safety-wired (copper wire) to the "NORM" position. When in the "OFF" position, the GPWS is disabled and allows abnormal landings, that involve flap problems or zero-flap, to occur without the GPWS warning going off during the approach (flap position is one of several parameters monitored by GPWS). This panel is also sometimes located elsewhere on the overhead and, on some aircraft, it can be found on the lower Flight Engineer (FE) panel. There is a "GPWS" amber light that indicates system problems on the "Door Warning" light panel located on the lower FE panel as well. When a GPWS dynamic warning is tripped, the pilot/co-pilot have their own "Pull Up" and "Below Glideslope" indicators on their respective panels that will illuminate accordingly along with the aural warning.

Thanks for mentioning it, but I already have the -100 peculiar landing gear panel plus light module but did not include it in the picture due to it being stored in a box at the moment (I also have the gear handle itself). At the moment, I do not have the physical space in the apartment to properly set-up my instrument panel until I move to a bigger place, probably later this year. Right now, I work on the panels and other stuff individually as I get them ready for integration into a full-blown panel set-up sometime in the future. I also have the fire handle assembly and glareshield, but those are stored as well.

I temporarily put the panels against the wall for the purpose of getting the pictures, so I could show them here.

Rick

[Michael Carter]

That must be particular to the -100 series. The -200 GPWS "GPWS--OFF, NORM" is controlled only on the FE panel or by a CB. I'd have to check which P-panel it's on. The -200 includes a test panel with a single push-button and Korry indicator and the failure annunciator can be found on some models integrated with the overhead speaker panel. On others, it's on the left (right) MIP. I guess it depends on when it was built and what the customer specified.

The PULL UP and BELOW G/S warnings are located in various locations on the -200. Mine are located just above the right side of the A/S indicator, though I have seen them farther over on the left panel where my windshear indicators are and below the VSI on others.

It's like trying to re-build a '70 455 Stage1 Buick GS from the ground up without a build sheet.

[3-Holer]

You are so right regarding the never-ending configurations of various items on the 727! Between the various models, different customer configurations, and the changes made by the new owners as the aircraft changed hands, it does become hard to nail down one standard cockpit set-up. Then there is TWA. They just had to be different so they went as far as re-designing many of the standard 727 modules; this can be readily seen by looking at a TWA Flight Engineer panel; many changes compared to standard panels.

My panel came from a 727-23, which was intially delivered to AA. I intially tried to configure the panel and all instruments to the same type used by AA. I have an AA Flight Manual that is specific to these aircraft (by registration number) so have an excellent source for what the original panel had. Unfortunately, not all the original components are available. For example, the airspeed indicators are not like the originals because they are combination airspeed/mach meters. The original configuration had separate airspeed and mach indicators; this explains the instrument covers to the immediate left of the airspeed indicators, which is where the mach meter was installed. Tracking down the 727-specific surface position indicator was another long wait; there are several versions of this instrument as well....it never stops!!!

I hit pay-dirt a few years ago when I came across the True Airspeed (TAS)/Static Air Temperature (SAT) indicator that is mounted to the left of the co-pilot's RMI; this is a very unique design indicator that was used on many AA aircraft, including their 727-23 and 707's. Needless to say, I was very happy to find this rare gem!

I still need the combination "Pull Up" and "Below Glideslope" lens; the ones installed (lower right corner of each panel) do not have those words. I may have to make those myself.

Anyway, as they say, "a work in progress"...

Rick

One unfortunate problem is that the center panel did not come from the same aircraft as the left/right panels!! It is close but is configured differently then the 727-23.